external image chandra_magic.en.jpg

Measuring the electromagnetic spectrum
You actually know more about it than you may think!

The electromagnetic (EM) spectrum is just a name that scientists give a bunch of types of radiation when they want to talk about them as a group. Radiation is energy that travels and spreads out as it goes-- visible light that comes from a lamp in your house and radio waves that come from a radio station are two types of
electromagnetic radiation.

Other examples of EM radiation are microwaves, infrared andultraviolet light, X-rays and gamma-rays. Hotter, more energetic objects and events create higher energy radiation than cool objects. Only extremely hot objects or particles moving at very high velocities can create high-energy radiation like X-rays and gamma-rays.


Videos, Tutorials, and Other Information:






NASA's Website on the Electromagnetic Spectrum

PowerPoint:


Other Information:


Here are the different types of radiation in the EM spectrum, in order from lowest energy to highest:

Radio
Radio

Radio: Yes, this is the same kind of energy that radio stations emit into the air for your boom box to capture and turn into your favorite Mozart, Madonna, or Justin Timberlake tunes. But radio waves are also emitted by other things ... such as stars and gases in space. You may not be able to dance to what these objects emit, but you can use it to learn what they are made of.
Microwave
Microwave

Microwaves: They will cook your popcorn in just a few minutes! Microwaves in space are used by astronomers to learn about the structure of nearby galaxies, and our own Milky Way!
Infrared to UV
Infrared to UV

Infrared: Our skin emits infrared light, which is why we can be seen in the dark by someone using night vision goggles. In space, IR light maps the dust between stars.


Visible: Yes, this is the part that our eyes see. Visible radiation is emitted by everything from fireflies to light bulbs to stars ... also by fast-moving particles hitting other particles.


Ultraviolet: We know that the Sun is a source of ultraviolet (or UV) radiation, because it is the UV rays that cause our skin to burn! Stars and other "hot" objects in space emit UV radiation.
X-ray
X-ray

X-rays: Your doctor uses them to look at your bones and your dentist to look at your teeth. Hot gases in theUniverse also emit X-rays .
Gamma-ray
Gamma-ray

Gamma-rays: Radioactive materials (some natural and others made by man in things like nuclear power plants) can emit gamma-rays. Big particle accelerators that scientists use to help them understand what matter is made of can sometimes generate gamma-rays. But the biggest gamma-ray generator of all is the Universe! It makes gamma radiation in all kinds of ways.

Understanding Energy Waves Website




ELECTROMAGNETIC SPECTRUM


Radios, televisions, mobile phones, and radar use signals made up of electromagnetic waves. These are waves that carry energy as electricity and magnetism at the speed of light. Light we can see is also an electromagnetic wave, but other types of electromagnetic waves are invisible. The various types of electromagnetic waves have different frequencies and wavelengths. Together, they make up the electromagnetic spectrum.



X-RAYS
X-RAYS

X-RAYS

These are high-energy waves that pass through flesh but not bone. In medicine, X-ray photographs are used to check people's bones for damage. In high doses, X-rays can harm people.












GAMMA RAYS


These are produced by radioactivity. They have a short wavelength and a high frequency and carry large amounts of energy. They are very harmful and can cause cancer in humans and animals.

external image Tsar-Nuclear-Explosion.jpg


ULTRAVIOLET RAYS


These invisible waves are slightly shorter than visible violet light and carry more energy. We wear sunglasses and sunblock to prevent damage to our eyes and skin by ultraviolet rays.
external image sssafety.jpg




INFRARED RAYS


Infrared rays are slightly longer waves than visible red light. Although we cannot see infrared, we can feel it as heat. When heat energy is transferred by radiation, it is carried by waves of infrared.



external image 4.gif





RADAR


Radar is a way of locating aeroplanes and ships using a type of radio waves called microwaves. These have much longer wavelengths than visible light. Cooking is another use for microwaves.
external image weather_radar_3x4.jpg




RADIO WAVES


Radio waves are the longest in the spectrum. They carry radio and TV signals around Earth. Radio waves from outer space are picked up by radio telescopes and used in studies of the universe.
external image n03.gif






Tutorials, Games and Videos

Electromagnetic Spectrum Overview
Electromagnetic Spectrum Tutorial
Who Wants to Be a Millionaire
Matching Game
Understanding the Electromagnetic Spectrum


Stable and Unstable Atoms

What happens?
Radiation and Unstable Atoms


Extension/Enrichment: